https://github.com/akkartik/mu/blob/main/407right-justify.mu
 1 # print 'n' with enough leading spaces to be right-justified in 'width'
 2 fn right-justify screen: (addr screen), n: int, _width: int {
 3   # tweak things for negative numbers
 4   var n-width/eax: int <- decimal-size n
 5   var width/ecx: int <- copy _width
 6   {
 7     compare n-width, width
 8     break-if->=
 9     print-grapheme screen, 0x20  # space
10     width <- decrement
11     loop
12   }
13   print-int32-decimal screen, n
14 }